Lens grinder



J. H. MARTIN LENS GRINDER Aug. 20, 1940.

Filed Dec. 20, 1938 4 Sheets-Sheet l INVENTOR.

ATTORNEYS.

J. H. MARTIN LENS GR INDER Aug. 20, 1940.

'4 Sheets-Sheet 2 Filed Dec. 20, 1938 \QlmNm IN V EN TOR.

I BY

I ATTORNEYS.

J. H. MARTIN Aug. 20, 1940.

was GRINDER Filed Dec. 20, 1938 4 Sheets-Sheet 3 I- w N w N Qm 1 l Wmilw mw V I dym v Ff In N 2 k 1 M W JEJMQWZZ'W/ INVENTOR.

ATTORNEYS.

J. H. MARTIN mus GRINDER Aug. 20, 1940.

Filed Dec. 20, 1958 4 Sheets-Sheet 4 ezgwflzik INVENTOR.

ATTORNEYS Patented Aug. 20, 1940 UNITED STATES PATENT OFFICE.

was GRINDER Joseph Barry Martin, Roanoke, v... Application December 20,1938, Serial No. 246,887

4Claims.

The objects of this invention include the provision of a simple buteffective mechanism whereby any curvature may be ground into a lens,without changing grinding wheels, and with a flatsurfaced wheel, novelmeans being supplied for mounting and actuating the movable parts insuch a way that the result above alluded to may be accomplished.

It is within the province of the disclosure to improve generally and toenhance the utility of devices of that type to which the presentinvention appertains.

With the above and other objects in view, which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment of the invention herein disclosed, may be made within thescope of what is claimed, without depart: ing from the spirit of theinvention.

In the drawings:

Fig. 1 shows, in side elevation, a lens grinder constructed inaccordance with the invention;

Fig. 2 is a top plan;

Fig. 8 is a fragmental section on the line 33 of Fig. 2;

Fig. 4 is a front end elevation;

Fig. 5 is a section on the line H of Fig. 1;

Fig. 6 is a section on the line 6-4 of Fig. 2;

Fig. 7 is a section on the line 1-1 of Fig. 6;

Fig. 8 is an elevation showing a modification;

Fig. 9 is a diagrammatic view referred to in connection with thedescription of the operation of the device. I

For convenience in describing the relative locations of parts, that endof the machine to which the reference character A is applied will beconsidered the forward end, the rear end of the machine being marked bythe reference character B.

The device forming the subject matter of this application comprises abed I (Fig. 1) secured by legs 2 to a table 3. Near its forward end(Fig. 2) the bed I is supplied with a laterally extended and upwardlyprojecting bearing standard 4 (Fig. 4) and in the bearing 4, a shaft 5is journaled, the shaft being disposed transversely with respect to thelength of the machine. A grinding wheel 3 is secured to thrinner end ofthe shaft 5 and is disposed in the longitudinal axis of the machine asshown in Fig. 2.

The shaft 5 is supplied (Fig. 4) at its outer end, with a worm I,meshing with a worm wheel 8 journaled on a shaft 9 carried by an arm itprojecting outwardly from the bearing standard 4.

A drive shaft ll (Fig. 2) is supported for rotation in any suitable way(not shown) and is located below the table I. A belt and pulley drive 5l2, depicted in Figs. 1 and 2, constitutes means whereby rotation isimparted to the shaft 5 and the grinding wheel 6 from the shaft ll.

A slide or support I 4 (Fig. 3) is mounted for right lineadjustment,toward and away from the 10 grinding wheel 6, in a guideway (Fig. 5)formed in the bed I. For the adjustment of the slide I 4, toward andaway from the grinding wheel 6, there is provided such a mechanism as afeed screw II (Fig. 3) threaded into the slide ll, and held for rotationbut against longitudinal movement in the rear end of the bed I. Anelongated base member l6 (Fig. 2) is located above the slide I4 and bedI, and intermediate its ends, the base member I6 is mounted to swinghorizontally, and transversely of the plane of rotation of the grindingwheel 6, on a fulcrum screw I1 (Fig. 3) carried by the slide it.

A bracket l8 (Figs. 1 and 4) is secured to the forward end of the basepiece It and may be consideredpart thereof. On the forward portion ofthe bracket I8 (Figs. 1 and 4) there is secured an upstanding post IS. Atransverse pitman (Figs. 4 and 2) is provided, the inner end of thepitman 20 being connected by a ball and socket joint to the post l8.Figures 4 and 1 show that a crank 2| is connected to the worm wheel 8,to turn therewith. The outer end of the pitman 2' is connected at 22(Fig. 4) to the crank 2], for adjustment longitudinally of the crank.

The numeral 23 marks a carriage (Figs. 1 and 4), the carriage comprisingan elongated base 24 and upwardly projecting standards 25. As shown inFigs. 4 and 5, for instance, the base 24 of the carriage 23 is mountedon the member It for adjustment longitudinally thereof, toward and awayfrom the grinding wheel 6. A set screw 28 or other holding device(Fig, 1) carried by the base 24 of the carriage 23, maintains thecarriage in any position to which it may have been ad- 5 justed,lengthwise of the member l6. Figure 2 shows that at one side the base 24of the carriage 23 is provided with a longitudinal scale 2l, adapted tocooperate with an index 28 secured to the edge of the base piece l6. 50

The standards of the carriage 23 carry a fulcrum pin 29 (Fig. 2) onwhich a lever or guide 30 is mounted, between the standards 25, forvertical swinging movement, that is, in a direction at right angles to'the axis of rotation of the grind- 55 ing wheel 3. Figure shows that thelever 33 is the grinding wheel 3.

trough-shaped in cross section.

Mounted for longitudinal adjustment in the trough-shaped lever 33 is theshank 31 (Figs. 1, 2 and 5) of a work carrier 32, including an arcuatehead 33 (F18. l) convexed longitudinally toward The lens blocks L whichare to be ground, are cemented or secured otherwise to the head 33 ofthe work carrier 32. It

appears in Fig. 2 that shank 3i of the work carrier 32 is supplied withan elongated slot 34, co-

operating with a holding device 33 on the lever,

33, to retain the work carrier 32 in any position to which it may havebeen adjusted lengthwise.

On the upper surface of thelever 33 there is a longitudinal scale 33(Fig. 2), cooperating with an index 31 on arier 32.

Figures 1 and 6,show that a transverse shaft 33 is mounted to turn in alateral tubular ;bearing 33 (Fig. 2) which is carried by one of thestandards ,23 of the carriage 23. The shaft 33 is driven from the powershaft II, by a belt and pulley connection 43, shown in Figs. 2 and l.

h A pinion 4| (Figs. 6,4 and 5) is secured.to the inner end of the shaft38 and meshes with a gear'wheel 42, journaled on a stub shaft.

.(Fig. 7) mounted in one of the standards of the carriage 23. The gearwheel 42 is supplied with a circular, eccentric track 44 (Fig. 6)receiving a roller projection 43 (Fig. 7) carried by the lever 33 (Fig.l) and located behind the element 28 on which the lever swingsvertically with respect to the carriage 23. I

Bymeans of the feed screw I! of Figs. 1 and 3, the slide l4 can beadjusted to bring the lens blocks L up to the grinding wheel 3, the feedscrew constituting means for producing relative movement between thework carrier 32 and the wheel 3, to position the lens blocks L properlyfor grinding. When the slide I4 is advanced with respect to the grindingwheel 3, the parts participating in that movement are the base memberl3, the carriage 23, the lever 30 carrier 32. I 1

- -As to the rotation of the grinding wheel 6, that operation is broughtabout by the belt and pulley l2 of Figs. 1 and 2, the grinding wheelshaft 3, and the drive shaft ll.

The lateralswinging movement of the base member l3 (Fig. 2) on the pivotscrew I1 that is carried by the slide I4, is accomplished by a train ofparts including the bracket i3 (Fig. 1) on the forward end of the basemember it, the post I! of Fig. 4, the pitman 20. the connection 22, thecrank 2|, and the worm wheel 3, the worm wheel being rotated by the wormI on the grinding wheel shaft 3. 1

The vertical swinging movement of the work carrier 32 is produced by atrain of parts including the drive shaft ll of Fig. 2, the belt andpulley drive 43-of Fig. l, the shaft 38, the pinion 4! (Fig. 6) the gearwheel 42 supported at 43 on one of the standards 25 of the carriage 23,the eccentric groove or track 44 on the pinion 42, and the rollerprojection 43 which is carried by the lever 33 of Fig. 1, verticaltilting movement being imparted to the lever 30, on its fulcrum 23, thework carrier 32 participating in the vertical tilting movement of thelever 33.

The character 1' may be taken to represent the radius of curvaturelongitudinally of the axis ing the shank 3i of'the work carrier 32 inthe the shank 3| of the work car-v and the work -the "6 mark on thescale 33. The radius r,

The character B may be taken to represent the radius of curvature alongthe axisX-X of Fig. 9, the origin of the radius It being the fulcrum pin29 that connects the lever 33 to the standards 23 of the carriage 23.The grinding to produce cur- I vature on the radius r is brought aboutby the lateral swinging movement of the base member It on the fulcrumscrew ll of Figs. 2 and l, and the grinding to produce the curvature onthe radius R is brought about by the vertical swinging movement of thelever 30 and the work carrier 32 with respect to the fulcrum 23 of thelever.

The radius R can be varied in length by shiftof the index 23 and thescale 23 of Fig. 2.

Lens blocks for the kind of work done in the machine herein disclosed,come to the optician from the manufacturer .with the inside surface (thesurface cemented to the head 33 of the work carrier 32) finished to aminus six diopter curve. Figure 2 shows the machine set for grinding apiano lens. The index 23 registers with the 6 mark on the scale 21, andthe index 31 registers with the 6" mark on the scale 33. The outside ofthe lens block will be ground to a plus six diopter curve, but since theinside curve is a neutralizing, minus six diopter curve, the resultingproduct will be a piano lens.

In order to grind a piano-cylinder, the radius R, representing thevertical swing of the work carrier 32 longitudinally of th( axis X-X,remains unchanged, the index 31 cooperating with representing thehorizontal swing of the base member i6 and all parts carried by it,longitudinally of the aids Y-Y, is changed, say by moving the carriage23 until the index 23 cooperates with the 7" mark on the scale 21. Theresulting product is a plus one diopter cylinder.

In order to grind a compound surface, the work holder 32 is moved until,forexample, the index 31 cooperates with the 7'? mark on the scale 36,the radius R being altered. The carriage '23 is moved until, forinstance, the index 23 cooperates with the "8" mark on the scale 21. Theresulting product will have a plus 0!l8 diopter sphere combined with aplus one diopter cylinder.

The foregoing examples make manifest the possibilities of the machine ingrinding curves other than those specified. Especial attention isdirected to the fact thatthe device grinds a cylinder and a sphere onthe, same surface in one operation in an arc, the origin of the radiusof Q the arc in Fig. 1 being the fulcrum member 23, and the origin ofthe radius of the arc in Fig. 3 being the axis of rotation of the shaft23a.

The construction of the machine is such that any desired curvature maybe ground, regardless of the shape of the wheel 3, that is, whether thewheel is flat, convexed transversely at its periphcry, or even if thewheel 6 was of irregular shape,

because it happens to be somewhat out of condition at its circumference.The curves of the lens surface do not depend upon the configuration ofthe grinding wheel.

In Fig. 8 of the drawings, parts hereinbefore described have beendesignated by numerals already used with the suffix a. In this form ofthe invention, the fulcrum member 29 of Fig. 1 becomes a power drivenshaft 290, operated by a pulley 46 and a belt 41, the work carrier 32abeing a wheel, to the periphery of which the lens blocks are attached.The work carrier 32a receives continuous rotary motion, instead of theoscillating motion imparted to the work carrier 32 of Fig. 1, but ineither form of the invention, the lens blocks are presented to thegrinding wheel.

What is claimed is:

1. In a machine for grinding lenses of different curvatures on a singlegrinding wheel, a grinding wheel, means for mounting the grinding wheelfor rotation about an axis, a support, a base member, pivot meansmounting the base member on the support for swinging movement in a planedisposed substantially parallel to the axis of rotation of the grindingwheel, a carriage, means for mounting the carriage on the base memberfor right-line adjustment toward and fromthe pivot means, a lens carrierincluding a part holding a lens block in operative relation to theperiphery of the grinding wheel, and means for so mounting the lenscarrier on the carriage that said part of the lens carrier can move inan arc and in a plane substantially at right angles to the axis ofrotation of the grinding wheel, the lens carrier participating in theaforesaid movement of the carriage, toward and from the periphery of thegrinding wheel, and participating in the aforesaid right-line adjustmentof the carriage with respect to the pivot means.

2. A machine for grinding lenses of different curvatures on a singlegrinding wheel, constructed as set forth in claim 1, in combination withmechanism independent of the means for mounting the carriage on the basefor right-line adjustm'ent toward and from the pivot means, for mountingthe support and the grinding wheel for relative movement toward and awayfrom each other, thereby to secure a grinding relation betweenthegrinding wheel and a lens block on said part of the lens carrier.

3. A machine for grinding lenses of different curvatures on a singlegrinding WheeLconstructed as set forth in claim 1, and wherein the meansfor mounting the lens carrier as set forth in claim 1 is a guidesupported on the carriage for tilting movement about an axissubstantially parallel to the axis of rotation of the grinding wheel,the lens carrier embodying an elongated shank, and means for mountingthe shank for longitudinal adjustment on the guide.

4. In a machine for grinding lenses of diiferent curvatures on a singlegrinding wheel, a grinding wheel, means for mounting the grinding wheelfor rotation about an axis, a support, a base member, pivot meansmounting the base member on the support for swinging movement in a planedisposed substantially parallel to the axis of rotation of the grindingwheel, a carriage, means for mounting the carriage on the base memberfor right-line adjustment toward and from the pivot means, a guidemounted on the carriage for oscillating movement about an axis disposedsubstantially parallel to the axis of rotation of the grinding wheel, alens carrier including a part holding a lens block in opera- JOSEPHHARRY

